Coexisting carbonate-bearing eclogite and blueschist in SW Tianshan, China: Petrology and phase equilibria

► Eclogites and blueschists coexist at the same peak metamorphic conditions. ► The peak metamorphic conditions were estimated at 540-565 °C and 21.8-23.1 kbar. ► Peak metamorphic mineral assemblages are in equilibrium with an aqueous fluid phase. ► Eclogite and blueschist stability is due to their different bulk-rock compositions. ► Prograde, retrograde and eclogite-facies blueschists occur in SW Tianshan.